A cat (or other domesticated animal) which is neither spayed, neutered, given shots, or altered in any way whatsoever. Thereby giving it the potential to grow uninhibited and naturally. Resulting in a happy, healthy, smart companion. Think about it. Your parents didn't cut off your nuts. They left that decision up to you. Why then, should we be able to decide the fate of others? Especially those who can't speak or defend themselves. Just because we have the ability, doesn't mean we have the right.
My cat Mogi proudly has his nuts, eats holistic food, and is quite larger than most cats with an especially large head. He is very intelligent and emotional and knows how to correctly express himself to me. Naturalism is the only way. :)